This is a pilot study (30 patients) of a multicenter study (600 patients) of hypertension control and myocardial function in PD and HD. The power analysis is based on the hypothesis that a greater proportion of PD versus HD patients will demonstrate significant deterioration in echocardiographically defined left ventricular geometry and/or function. A significant deterioration, or change, is defined as at least 20% change in left ventricular mass over the time period set for each group.